Positive displacement boosters

ABSTRACT

A series of simple booster pumps operating as positive displacement pumps driven by either pneumatic or hydraulic power cylinders simply attached to the respective pump chambers which receive piston rods upon each cylinder stroke, controllable as to its length by an adjustable stop-plug thereby displacing fluid from pump chamber at pressures proportional to the ratios of rod diameters versus piston diameter, with or without integral check valves in the inlet or outlet ports of the pump chamber, with a shuttle valve built-in in the inlet port of the design for handling aerated fluids such as grease, eggnog or the like, and a built-in outlet check valve in the same pump chamber, and appropriate seals separating the actuation power cylinder from the pressurization pump chamber by a threaded connection representing the only means for connecting actuator to the pump chamber and providing simple booster pump construction with provisions for capacity change by virtue of interchanging cylinders from one size of a given maximum capacity to another size with completely different boosting and volume control capabilities, all with extreme easiness and simplicity, mandatory in pollution control equipment manufacture, among other vital applications.

White States went 1 1 1111 3,761,24

Pauliukonis Sept. 25, 1973 POSITIVE DISPLACEMENT BOOSTERS draulic power cylinders simply attached to the respec- [76] Inventor: Richard S. Pauliukonis, 6660 five punlp chambers which receive pis.ton rods upon Greenbriar Dr. Cleveland, Ohio each cylinder stroke, controllable as to its length by an 44130 adjustable stop-plug thereby displacing fluid from pump chamber at pressures proportional to the ratios Filedi 1971 of rod diameters versus piston diameter, with or without integral check valves in the inlet or outlet ports of [21] Appl- 204,916 the pump chamber, with a shuttle valve built-in in the inlet port of the design for handling aerated fluids such [52] US. Cl 417/401, 417/457, 417/511 35 grease, eggnog or the like, and a built-in outlet check [5 l Int. Cl. F04b 35/02 valve in the same pump chamber, and appropriate seals of Search 417/401, 457, 51 l separating the actuation power cylinder from the pressurization pump chamber by a threaded connection [56] References C ted representing the only means for connecting actuator to UNITED STATES PATENTS the pump chamber and providing simple booster pump 2,955,539 10/1960 Gardner 417/401 construction with Irovisions for capacity change by 3,609,061 9/1971 peoples U H 417/40; X tue of interchanging cylinders from one size of a given 1,351,505 8/1920 Cockroft 417/457 maximum capacity to another size with completely dif Primary Examiner-Al Lawrence Smith Assistant ExaminerRichard Sher ferent boosting and volume control capabilities, all with extreme easiness and simplicity, mandatory in pollution control equipment manufacture, among other vital applications.

4 Claims, 2 Drawing Figures PATENTEDsmSma 3,761,204

INVENTOR.

BY Emmet) PAuuuKfims POSITIVE DISPLACEMENT BOOSTERS The present invention pertains to a positive displacement pump actuated by a power cylinder for use with noncompressible fluids. The design allows for simplicity, accuracy, easy maintenance, versatility in application and in pump capacity variation, all at minimum cost.

The advantage of this type of positive displacement pumps is that the actuator is a simple power cylinder with varying cylinder stroke capability, enabling the control of pump volumetric capacity with ease.

The present invention provides positive displacement pumps which utilize power cylinders with piston rod extending into the cavity of a pump chamber and secured therein through the cylinder boss threaded into respective pump chamber end while O-ring separating said power cylinder boss from said pump chamber acts as a seal.

The fixed volume of liquid enclosed in the positive displacement pump chamber is trapped therein by check valves at both inlet and outlet ports. As the piston rod enters the pump chamber, the pressure created therein builds up until it overcomes the check valve pressure setting allowing for fluid exit through outlet port. The result is that the pump replaces an exact volume of fluid proportional to the volume of the piston rod continuously with constant accuracy because of no slippage and loss of volumetric efficiency common to pumps with piston rods provided with packing,upon each stroke&pump chamber refills with rod return.

Further, the invention can be adapted for use with areated pumping media such as grease,eggnog or the like by using a power cylinder with a modified piston rod end.

An additional objectof this invention is to provide booster pumps which can handle highly corrosive fluids such as acids, alkalis, other solutions or additives; because of the simplicity of design, the pump chamber can be made from materials compatible with such fluids, the piston rod entering the fluid can be treated with a Teflon spray or the like, and the seal separating the actuator-power cylinder from the pump chamber can be selected from an elastomer compativle with such fluids, all these adaptions are possible at minimum ex pense initially and in service. In one application the actuator-power cylinder can, for a bare minimum expense, be made from plastics by injection molding.

A further object of this invention is to provide a means of controlling piston rod stroke and volume by an internal, pressure balanced, stop-plug.

Devices of this type which require fewer components for pumping various fluids and improve ulti mate performance of the system are obviously desirable because theyprovide a simple, inexpensive and reliable means of displacing fluids with extreme accuracy at less cost initially and in service.

These and other objects and advantages of the invention will become more fully apparent from the following description of the embodiment of the invention, taken together with the accompanying drawings:

FIG. 1 identifies a cross-sectional view of a positive displacement pump wherein a pump chamber receives a single acting power cylinder with piston rod facing pump chamber'prop'erwhile attached thereto by means of simple'threaded cylinder rod-end boss provided with appropriate seal to separate the actuator from the pump chamber, and actuated by either air or hydraulic fluid pressure means entering cylinder end opposite the pump end and acting over exposed piston area of the piston-rod assembly of which other rod end enters said pump chamber exerting pressure considerably larger than the pressure applied to the piston, and proportional to the respective piston and piston rod areas, thus providing a rather large mechanical advantage to result in booster action inside pump chamber with relatively low operating pressure of the working fluid, be it hydraulic fluid or compressed air. Symbols of check valves shown in drawing FIG. 1 identify externally detachable directional check valves this pump requires for proper operation.

FIG. 2 illustrates a modified pump cross-sectional view wherein the single acting cylinder entering pump chamber is provided with appropriate piston-rod-seal to generate suction as well as to control inlet porting by a built-in shuttle valve in lieu of external detachable directional check valve, and to provide means of pumping not only non-compressible liquids but also to handle areated fluids such as eggnog, grease, etc.,etc., in an efficient and rather simple fashion while the outlet port is provided with integral check valve of adjustable design providing pumping means that require no external check valves and enable control of boosting pressures in the ratios of the areas of piston exposed to the working fluid versus the piston rod entering the pump chamber cavity.

As can be seen from FIG. 1 there are basically two components, a pump chamber 1 and a power cylinder 2 coupled together through a cylinders boss 3 provided with appropriate seal 4.

When cylinder becomes energized by the working fluid, the pumping fluid initiates and continues to flow via pump chamber cavities'from inlet port to outlet port for as long as the'cylinder continues to strok e,filling up & expelling media pumped. The pump chamber 1 of elongated configuration is provided with a continuous centtrally located circular bore 5 which is threaded along its length to receive at one pump chamber end 6 and cylinder boss 3 and at the other chamber end l0-an end plug 7, also threaded in the case illustrated. The extremeties of this threaded bore 5 are provided at each end with thread reliefs 8 of large enough size to receive appropriate seals 4 and 9 respectively. Port 11 with symbolic check valve 13 identifies fluid supply port means,and port 12 with check valve symbol 14 shows the exit port means for fluid pumped with directional identification shown therein. Inside pump chamber 5 there is an axially adjustable threaded stop 15 with segments 16 of threads removed to permit fluid communicationon both sides of said stop, including adjusting slot '17 for screw driver adjustment when needed,by simply removing end plug 7 for an easy access and axial position change of stop 15. In operation, with plug 7 tightly secured and the stop 15 positioned at the desired distance away from the plug end, the stop will act as a restrictor for piston rod travel inside the pump chamber 5 and thus control the displacement while the fluid pressure is equalized via segmented openings of stop 15, reducing strain exerted by piston-rod over the stop 15 during the pump operation.

The cylinder 2 of elongated configuration, in the illustrated case of FIG. 1, identifies tubular housing 18 one end of which is provided with port 19 for supply of the working fluid to the housing interior 20 where a piston rod asembly 21 is located,while the other housing end is threaded as shown by 22 to receive rod end 23 permanently secured thereto and terminating with a boss 3 which externally is threaded to enter pump chamber and to carry seal 4 ,and internally is provided with a groove 25 retaining rod seal 26 of the piston rod 27 which is attached to the piston 28 of the piston rod assembly 21 and which protrudes into the pump chamber bore 5 for subsequent pumping when the working fluid enters fluid supply port 19.Spring 29 inside tubular housing 18 situated against the piston 28 at one end and at other end-inside a cavity 30,returns the piston rod assembly 21 into original positon for pump priming when pressure from port 19 is removed, constituting pump operation and displacement of pumping media from the pump chamber,such pumping media by necessity being non-compressible liquid which acts as a liquid spring to successfully continue pumping operation.

For pumping media with less liquid spring capability and lower bulk modulus of elasticity of the fluids pumped, the FIG. identifies pump modification which provides pump design with closer dimensions of the piston rod with pump chamber cavity, and with check valves integral with the pump chamber inlet & outlet ports. As can be seen from drawing, FIG. 2, there are two basic components comprising this pump, the pump chamber 51 and the power cylinder-actuator 52 coupled together through a cylinder boss 53 provided with an appropriate seal 54. When the cylinder-actuator becomes energized by a working fluid,be it pressurized air or hydraulic fluid, it pushes piston rod forward into the pump chamber cavity to act upon the pumping media for subsequent fluid compression and pumping through the passages provided in the pump chamber 51.

The pump chamber 51 is provided with alongated opening along the pump chamber length,one end of which is machined so as to receive the cylinder boss 53 with its seal and a shuttle valve circular member 55 slidably placed therein within the opening 56 which terminates with shoulder 66 of smaller opening 67 that gradually reduces in size via taper 68 to become opening 57 which is equivalent to the diameter of the diameter of the piston rod 58.

The opening 57 at the other pump chamber end becomes threaded as identified by 59 to receive an adjustment stop-plug 60 also threaded and machined on sides with flats 63 for pressure balance on both sides of the stop-plug 60 during the pump operation in order to reduce strain imposed by the piston rod end 580 which becomes restricted in its forward motion with resultant volumetric capacity control of the pump upon each stroke of the cylinder after the location of the stop-plug is determined by choice,and the volume displacement of the desired value is obtained, End cap 62 provided with appropriate seal 61 keeps the opening 57 shut.

Perpendicular to the smaller diameter central opening 67, there is a port 69 communicating with central opening 67 adjacent to the taper 68, which in the illustrated case enters a circular cavity 70 created by the taper 68 and the end of the shuttle valve member 55,also tapered,for fluid supply prior to actuating power cylinder-actuator 52 and before the pumping initiates.Port 71 acts as supply port for pumping media and provides the necessary fluid to be pumped to the port 69 and cavity 70 at the time the piston rod end 58a retracts,creating a void in the cavity 70 and the opening 57. Another perpendicularly situated port 72 in communication with the opening 57 serves as pump purging -air venting means during the pump priming. A continuation of port 72 cutting across the opening 57 results in an opening 72a which in the illustrated case is in communication with appropriate passage 73 housing the exhaust check valving means 74 leading to exhaust port 75.

The check valving means comprise a spool 76 provided with appropriate seals 77 of O-ring configuration and a spring 78 which can be preloaded by appropriate nut 79, all integrally mounted inside the pump chamber body for an easy access and adjustment.

Adjustment of volume is done by unscrewing the end cap 62 and moving the stop-plug 60 axially either forward or backward by means of a screw driver inserted into the slot 80 of the stop-plug 60, and closing the end cap 62 shut thereafter. Pressure control is obtained by manipulating screw nut 79 which either loosens or tightens the spring 78 and controls the ultimate location of the spool 76 during the pump operation when cylinder becomes energized.

The power cylindenactuator 52 represents a standard power cylinder with piston rod modifications to suit the requirements set forth in this invention whereby the shuttle valve has to be actuated by means of such rod modification.

As can be seen from FIG. 2, the cylinder 52 of elongated configuration identifies a tubular housing 81 one end of which is provided with port 82 for supply of the working fluid to the housing interior 83 where a piston 84 with appropriate seald 85 is located, while the other housing end is threaded as shown by 86 to receive rod end 87 permanently secured thereto and terminating with boss 53 which externally is threaded to enter pump chamber 51 and to carry seal 54, and internally is provided with a groove 88 retaining piston rod seal 89 of the piston rod 58 which is permanently attached to the piston 84 at one end and protrudes into the pump chamber bore fit up with a shuttle valve member 55 at the other end. The protruding piston rod end 58 is grooved at distance equivalent to the length of the shuttle valve member 55 and provided with piston rod end seal 90 which is designed to enter shuttle valve member 55 opening 55a tightly. This enables moving shuttle valve member 55 forward with each piston rod motion when the piston receives pressure energy supplied to the cylinder 52 via port 82 to initiate pumping,concurrently closing pump chamber circular cavity 70 and, upon further progress of piston rod slidable motion inwardly towards the pump cavity,to pressurize the contents trapped inside the circular opening 57 until the pressure therein increases above that of the exhaust check-valve-setting to initiate and to continue pumping at volumes predetermined by the setting of the stopplug 60. Spring 91 placed inside the cylinder and over the piston rod against the piston 84 at one end and inside rod end cavity 92 at the other spring end returns the piston rod end 58 to the original position for pump priming and filling up cavity 70 for subsequent pumping upon supply of pressurized fluid into the cylinder port 82 to actuate piston 84,and continue so for as long as the cycle repeats pumping the fluid flowed via pump chamber ports initiating with port 71 and continuing through the port 69, the cavity 70,the opening 57 and out through the port 75 via opening 72a and passage 73 housing exhaust check valve 74.

This invention is not restricted to the slavish imitation of each and every one of the details described above which have been set forth merely by way of example with intent of most clearly setting forth the teachings of the invention.Obviously, devices may be provided which change, eliminate, add certain specific structural details without departing from the spirit of this invention.

What is claimed is:

l. A positive displacement booster pump comprising: a power cylinder having a power piston slidably disposed therein,a fluid supply and exhaust port provided at one end of the power cylinder for actuation of said power piston, a piston rod of a diameter less than said piston connected to said piston on the side opposite the supply and exhaust port, said piston rod extending through a cylinder-rod end boss at the other end of the power cylinder, said cylinder-rod end boss being externally threaded and provided with an external seal groove with a seal disposed therein, a compression spring disposed around said piston rod, one end of said spring abutting the power piston and the other end abutting an elongated end closure member,.said end closure member having a central opening for accomodation of said piston rod and being internally threaded for mating with said power cylinder, a sealing groove in said end closure member having a seal disposed therein for sliding engagement with said piston rod, the opposite end of said end closure member being threaded exchamber and axially positioned bylrotation thereof, an adjusting slot provided in said stop member to facilitate rotation, whereby the postion of said stop member determines the length of travel of said piston rod and thus the volumetric displacement of teh pump chamber, a passage extending through said stop member to equalize the pressure on both sides thereof.

2. A positive displacement booster pump as defined in claim 1 including valve means in said inlet and outlet means of said pump chamber, said valve means in said inletmeans having a circular shuttle valve member disposed around said piston rod inside said pump chamber, one end of said shuttle member shouldered externally and slightly tapered internally abutting said cylinder-rod end boss when the piston rod is in the retracted position and the other end of said shuttle member tapered, a seal in a peripheral groove of said piston rod in the vicinity of said shuttle shoulder for the frictional engagement and the position change of the shuttle, said pump chamber having an enlarged portion terminating with a tapered inner end wall at said inlet means and being adapted to slidably receive said shuttle, said shuttle closing said inlet means when the piston rod is in the extended position with the respective tapers of the shuttle member and the enlarged portion of the central bore meeting, an air vent means entering said pump chamber through a side wall, check valve means in said outlet means including spring adjustment for pressure ternally and provided with a peripheral groove with a Control through a spool with seals disposed around said seal disposed therein, a vent in said end closure member, an elongated pump chamber being internally threaded at one end for mating with said end closure member, inlet and outlet means in said pump chamber, the other end of said pump chamber'being internally threaded and having an externally threaded plug secured therein, a seal disposed around said plug, an ex ternally threaded stop member disposed in said pump spool.

3. A positive displacement booster pump as defined in claim 1 wherein said power cylinder is made from anticorrosive materials including plastics.

4. A positive displacementbooster pump as defined in claim 1 wherein said pump chamber is made from plastics. 

1. A positive displacement booster pump comprising: a power cylinder having a power piston slidably disposed therein,a fluid supply and exhaust port provided at one end of the power cylinder for actuation of said power piston, a piston rod of a diameter less than said piston connected to said piston on the side opposite the supply and exhaust port, said piston rod extending through a cylinder-rod end boss at the other end of the power cylinder, said cylinder-rod end boss being externally threaded and provided with an external seal groove with a seal disposed therein, a compression spring disposed around said piston rod, one end of said spring abutting the power piston and the other end abutting an elongated end closure member, said end closure member having a central opening for accomodation of said piston rod and being internally threaded for mating with said power cylinder, a sealing groove in said end closure member having a seal disposed therein for sliding engagement with said piston rod, the opposite end of said end closure member being threaded externally and provided with a peripheral groove with a seal disposed therein, a vent in said end closure member, an elongated pump chamber being internally threaded at one end for mating with said end closure member, inlet and outlet means in said pump chamber, the other end of said pump chamber being internally threaded and having an externally threaded plug secured therein, a seal disposed around said plug, an externally threaded stop member disposed in said pump chamber and axially positioned by rotation thereof, an adjusting slot provided in said stop member to facilitate rotation, whereby the postion of said stop member determines the length of travel of said piston rod and thus the volumetric displacement of teh pump chamber, a passage extending through said stop member to equalize the pressure on both sides thereof.
 2. A positive displacement booster pump as defined in claim 1 including valve means in said inlet and outlet means of said pump chamber, said valve means in said inlet means having a circular shuttle valve member disposed around said piston rod inside said pump chamber, one end of said shuttle member shouldered externally and slightly tapered internally abutting said cylinder-rod end boss when the piston rod is in the retracted position and the other end of said shuttle member tapered, a seal in a peripheral groove of said piston rod in the vicinity of said shuttle shoulder for the frictional engagement and the position change of the shuttle, said pump chamber having an enlarged portion terminating with a tapered inner end wall at said inlet means and being adapted to slidably receive said shuttle, said shuttle closing said inlet means when the piston rod is in the extended position with the respective tapers of the shuttle member and the enlarged portion of the central bore meeting, an air vent means entering said pump chamber through a side wall, check valve means in said outlet means including spring adjustment for pressure control through a spool with seals disposed around said spool.
 3. A positive displacement booster pump as defined in claim 1 wherein said power cylinder is made from anticorrosive materials including plastics.
 4. A positive displacement booster pump as defined in claim 1 wherein said pump chamber is made from plastics. 